1. Field of The Invention
The invention relates to contacts for use with an IC memory card, particularly to a contact having a smooth and symmetrical configuration which disperses applied stress evenly thus reducing the phenomenon of stress concentration and balancing a male contact therein.
2. The Prior Art
IC memory cards are gradually and popularly used in the market due to their compact size and tremendous memory capacity. As shown in FIGS. 1 and 2, such memory card includes a board 11 with a soldered IC chip 11a thereon and enclosed within a protection shield 10 wherein a set of connection section is positioned on the front portion for connection with a connector 20 which is mounted on and electrically communicates with a main board 21 for operation with the inserted memory card. It can be understood that the connection between the female contact 31 of the memory card 10 and the male contact 80 of the complementary connector 20 is an important factor affecting the precision of the signal transmission between the memory card 10 and the main board 21. Moreover, it is appreciated that the configuration of a socket-type female contact 31 is the key point for determining if such female contact has a good mechanical and electrical connection with a generally pin-type male contact 80 of the connector 20 inserted therein.
One type prior art socket-type female contact 31 of the memory card, as shown in FIGS. 3 and 4, comprises a pair of parallel beams 32 respectively joined on tow U-shaped sections 33 by their two opposite ends 34 for retaining a pin-type male contact 80 therebetween. Referring to FIG. 4, the male contact 80 may swing therein in the lateral direction thus affecting the stability of the signal transmission. Additionally, each beam 32 has a narrowed root, i.e., end 34, connected to the corresponding U-shaped section 33 and a wider connection portion in the midst. The expanded contact portion in the midst where the cross-sectional view FIG. 4 is taken from, is good for the connection between the pin-type male contact 80 and the female contact 31 thereabout, but otherwise a relatively larger stress will occur around the end 34 portion, thus affecting the performance of the whole configuration of the female contact 31.
Shown in FIGS. 5,6(A) and 6(B) is another type prior art female contact 31' which has a pair of opposite beams 320, 322 jointly connected to each other through a pair of square type sections positioned at two opposite ends 33' thereof, respectively, wherein the upper beam 320 is composed of a left half 321 and a right half 322 which are juxtaposed with each other. Referring to FIGS. 6(A) and 6(B), although the left half 321 and the right half 322 are intentionally side by side positioned together without any space therebetween to form as an integrity corresponding to the lower beam 322 for a symmetrical and even whole configuration in order to obtain a better retention with the male contact 80, unfortunately, in an actual manufacturing process, it raises forming difficulties and complicates the plating procedure of the female contact 31' without an space .alpha. between the opposite edges of the left half 321 and the right half 323. Accordingly, without much endeavor in manufacturing control, a defect of the female contact occurs thereof which forms a pair of separate sharp edges A' and A" beside the space .alpha. as shown in FIG. 6(B) which may scratch the inserted male contact 80, instead of a purposive type as shown in FIG. 6(A) where an joined edge A is met by these two opposite beams 321 and 323.
In according with this invention, a new design of the contact has advantages over the aforementioned prior art design. The female contact of the present invention can achieve a stable retention with a male contact without any stress concentration or unbalanced force dispersion which incurs self-bending moment of the pin-type male contact. The present invention can also be operated without any potential scratch damage of the male contact inserted therein.